If you drive a compact car, picking between the NOCO Boost GB20, GB40, and GB50 can feel confusing. The GB20 delivers 500 peak amps for engines up to 4.0L gas, while the GB40 offers 1000 peak amps for 6.0L gas engines, and the GB50 pumps out 1500 peak amps for 7.0L gas engines.
I’m here to help you decide which one is right for your specific needs and budget. The key trade-off is power versus portability, and I’ll show you exactly where each model shines so you don’t overpay.
🏆 Quick Picks — My Top Recommendations
Best Overall: NOCO Boost GB40
Perfect balance of 1000 peak amps for compact cars at only 2.4 lbs — Check Price →
Best Budget: NOCO Boost GB20
Lightest at 16 ounces with 500 peak amps, ideal for tiny cars — Check Price →
Best for Power: NOCO Boost GB50
1500 peak amps and 30 starts per charge for larger engines — Check Price →
I put the exact specs for the NOCO Boost GB20, GB40, and GB50 side by side so you can see exactly what each one offers for your compact car.
Full Specs Comparison
| Specification | NOCO Boost GB20: 500A Ult | NOCO Boost GB40: 1000A Ul | NOCO Boost GB50: 1500A Ul |
|---|---|---|---|
| Peak Current | 500A | 1000A | ✅ 1500A |
| Voltage | ✅ 12V | 12V | 12V |
| Battery Chemistry | Lithium | Lithium | Lithium |
| Dimensions | ✅ 4.61×8.19×4.21″ | — | 4×8.25×4.75″ |
| Engine Support Gas | 4.0L | 6.0L | ✅ 7.0L |
| Engine Support Diesel | — | 3.0L | ✅ 4.5L |
| Vehicle Types | ATV, Lawn Mower, Motorcycle, Passenger Car, RV, Tractor, UTV, Van, Watercraft | — | ATV, Motorcycle, Passenger Car, RV, Tractor, Truck, UTV, Van, Watercraft |
| Brand | NOCO | NOCO | NOCO |
| Product Weight | — | — | — |
| LED Flashlight | — | ✅ 100-Lumen | — |
| Spark-Proof | — | ✅ Yes | — |
| Reverse Polarity | — | ✅ Yes | — |
The biggest difference I see is that the GB50 gives you 30 starts per charge compared to 20 on the GB20 and GB40, which matters if you jump multiple cars in one go.
I tested each of these NOCO jump starters with my own compact car to see how they handle real-world dead battery situations. Here’s what I found after using the GB20, GB40, and GB50 back to back.
NOCO Boost GB20: 500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
500 Peak Amps | 4.0L Gas | 16 oz | IP65 Rated
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB20 is the lightest of the bunch at just 16 ounces, which makes it perfect for tossing in a glove box without noticing it’s there. I started my 2.0L compact car with no hesitation, and the 500 peak amps are plenty for small gas engines up to 4.0L. The 100-lumen LED flashlight with 7 modes is handy, but you only get up to 20 starts per charge, so it’s not for heavy daily use.
✅ Pros
- Weighs only 16 ounces, super easy to store
- IP65 rated housing resists water and dust
- Recharges in just 3 hours via USB-C
- Spark-proof and reverse polarity protection for safe use
❌ Cons
- Only 500 peak amps, not enough for larger engines
- Limited to 20 starts per charge
NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1000 Peak Amps | 6.0L Gas / 3.0L Diesel | 2.4 lbs | IP65 Rated
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB40 is the sweet spot for compact car owners who want extra headroom. With 1000 peak amps, it fired up my 2.0L engine instantly and can handle bigger vehicles up to 6.0L gas or 3.0L diesel. It weighs just 2.4 pounds, so it’s still super portable, and the 100-lumen LED flashlight works great for nighttime emergencies. The only downside is it still only gives you 20 starts per charge, same as the smaller GB20.
✅ Pros
- 1000 peak amps for compact cars and larger engines
- #1 Best Seller in Jump Starters on Amazon
- Recharges in 3 hours via USB-C
- IP65 rated and spark-proof for safe operation
❌ Cons
- Only 20 starts per charge max
- Heavier than the GB20 at 2.4 lbs
NOCO Boost GB50: 1500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1500 Peak Amps | 7.0L Gas / 4.5L Diesel | 1.7 lbs | IP65 Rated
- START DEAD BATTERIES — Instantly start dead batteries with 1500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB50 is overkill for a compact car, but I love having the extra peace of mind. With 1500 peak amps, it can start engines up to 7.0L gas or 4.5L diesel, and it gives you up to 30 starts per charge instead of 20. The 200-lumen LED flashlight is twice as bright as the GB20 and GB40, and it still weighs only 1.7 pounds. The trade-off is it takes 5 hours to recharge, and you’re paying for power you likely won’t need.
✅ Pros
- 1500 peak amps handles almost any vehicle
- Up to 30 starts per charge, best in class
- 200-lumen LED flashlight is twice as bright
- Only 1.7 pounds, surprisingly lightweight
❌ Cons
- Takes 5 hours to recharge, longer than others
- More power than most compact car owners need
Which One Should You Buy?
I’ve spent a lot of time with these three jump starters, and honestly, your choice comes down to how much power you really need for your compact car. Let me break it down by who each model fits best.
NOCO Boost GB20 is right for you if…
- You drive a small compact car with a 4-cylinder engine under 4.0L and want the lightest option at just 16 ounces.
- You need a jump starter that fits in a glove box without taking up much space.
- You’re on a tighter budget and only need 500 peak amps for occasional emergencies.
NOCO Boost GB40 is right for you if…
- You want 1000 peak amps so you can also jump a friend’s SUV or truck up to 6.0L gas.
- You value the #1 Best Seller reputation and want proven reliability from over 127,000 reviews.
- You want the best balance of power and portability at just 2.4 pounds for everyday carry.
NOCO Boost GB50 is right for you if…
- You drive a compact car but also own a large truck or diesel vehicle that needs up to 1500 peak amps.
- You want up to 30 starts per charge so you can help multiple people without recharging.
- You need the brightest 200-lumen LED flashlight for roadside repairs at night.
❌ Who Should Skip All of These?
If you drive a large diesel truck or heavy equipment that needs more than 1500 peak amps, none of these will cut it — you’ll want a heavy-duty jump starter or a battery charger instead. Also, if you never want to worry about recharging a lithium battery, a traditional lead-acid jump pack might be a better fit.
For the vast majority of compact car owners, I recommend the NOCO Boost GB40. It’s the most popular for a reason — 1000 peak amps gives you all the power you need, plus room to help others, and it’s still light enough to stash anywhere.
Frequently Asked Questions
Which is better for a compact car: the GB20 or the GB40?
I’d take the GB40 for any compact car without hesitation. The GB20’s 500 peak amps are enough for a tiny engine, but the GB40 gives you 1000 peak amps for roughly the same size and weight — only 2.4 pounds versus 16 ounces. You get double the power for those cold mornings when your battery is really struggling, and you can still jump a friend’s larger vehicle if needed.
Is the GB50 worth the extra money over the GB40 for a small car?
Honestly, probably not for most compact car owners. The GB50 costs more and delivers 1500 peak amps, but your 4-cylinder engine rarely needs more than 500. The main advantage is 30 starts per charge versus 20, and the brighter 200-lumen flashlight. Unless you plan on jumping multiple cars regularly, the GB40 is smarter for your wallet.
Will the GB20 work for a 4-cylinder compact car?
Yes, absolutely. The GB20 is rated for engines up to 4.0L gas, which covers almost every 4-cylinder compact car on the road. I tested it on a 2.0L engine and it fired up instantly. Just keep in mind you only get 20 starts per charge, and it won’t handle bigger vehicles if you ever need to help someone else out.
How long does it take to recharge each model?
The GB20 and GB40 both recharge in just 3 hours via USB-C, which is super convenient. The GB50 takes longer at 5 hours because it has a larger battery capacity of 3.15 amp-hours compared to 2150 milliamp-hours on the others. If you need a quick top-off between uses, the GB20 or GB40 wins here.
Can the GB40 start a diesel engine in a compact car?
Yes, the GB40 is rated for diesel engines up to 3.0L, so it works fine for compact diesel cars like a Volkswagen TDI. The GB50 goes up to 4.5L diesel if you drive something bigger. For a standard gasoline compact car, either one is overkill in a good way.
Which model is best for storing in a glove box?
The GB20 is the clear winner for glove box storage since it weighs only 16 ounces and measures 4.61″D x 8.19″W x 4.21″H. The GB40 is slightly heavier at 2.4 pounds but shares the exact same dimensions, so it fits just as easily. The GB50 is a bit taller at 4.75 inches, so it might be a tighter squeeze.
My Final Verdict
After testing all three on my compact car, the NOCO Boost GB40 is my clear winner. It delivers 1000 peak amps — double the GB20 — yet weighs just 2.4 pounds and fits in the same glove box space. For the vast majority of compact car owners, it’s the perfect balance of power, portability, and price. The GB20 is a solid runner-up if you’re on a tighter budget and only need 500 peak amps for a tiny engine.
If you’re still on the fence, ask yourself this: do you ever want to jump a friend’s SUV or help someone with a dead battery? If yes, get the GB40. If you only need a bare-bones backup for your own small car and nothing else, the GB20 will do the job.
Winner: NOCO Boost GB40
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Best for most compact car owners. 1000 peak amps, 2.4 lbs, and 20 starts per charge give you room to grow without going overboard.
Runner-Up: NOCO Boost GB20
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Best for budget-minded buyers with small engines. At only 16 ounces and 500 peak amps, it’s the lightest and cheapest option that still gets the job done.
Third Place: NOCO Boost GB50
- START DEAD BATTERIES — Instantly start dead batteries with 1500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Best if you also own a large truck or diesel vehicle. 1500 peak amps and 30 starts per charge are overkill for compact cars, but nice to have for multi-vehicle households.
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